Non-Cruiser tech - 85 Mustang GT problem

So about 2 months ago I bought this Mustang as another toy. It was a pretty much all original car in really good condition. Original roller cam 302 with EGR and smog, stock duraspark distributor, stock fuel pump, and the original Motorcraft/Holley 600 cfm carb. The suspension and brakes have now been modified, so it actually handles and stops now. But I keep having this strange problem that totally escapes me. A few times now it has had these fits where it sputters terribly, loses all power, and it sounds like it's backfiring through the carb. This has happened 3 times now, and each time it's after it's been run at real light load, or just left idling for a long time. But it's not overheating when this happens. One time after running along at 1500 rpm along the beach for about 45 minutes, one after sitting in traffic on a hot day, and over the weekend after idling in my driveway for about 40 minutes. Each time the car runs perfectly fine after it's shut off and cools down for about 30 minutes. I'm thinking of changing the intake and getting rid of the EGR, but I'm not sure if that's it. It's getting fuel and spark when it does this. Over the weekend I actually noticed there was fuel trickling from the screw on the top of the front fuel bowl on the carb when it was doing this. That can't be good either. Any ideas? Besides checking for fuel and spark, all i've actually changed is the fuel filter. Or I should say I installed a fuel filter, it was missing before.

Yeah, I think it would be way faster if I swapped a 2F in there. A 2F with injection would be pretty sweet. But if I had a 2F injection setup, it would be on my cruiser. Good point about the carb though. Maybe it's leaking out the top because there's a float problem and the thing is totally full to the top. That would be strange. On my first car back when I was 16 I messed with the floats and actually had fuel fill the carb (and maybe the intake too) and come out the top. That was quite a sight.

Oh man I totally thought you were busting my balls and meant a man a fre tbi setup. The mass air motors were actually not introduced 49 state until 89, and would be a good option, but I actually want to leave this car with a carb. Once they are sorted out, they seem to be much cheaper to keep going. Now that I have my crusier sorted it costs me very little to maintain. On one of the mustang forums a guy is saying it's vapor lock, so I'm going to check the return line. But I still suspect a problem in the EGR system. I'm hoping to make this car smog free and simple like my cruiser. Ditch the egr and smog pump, put a regular dual plane manifold on it, a 4160 holley to replace the stock 4180 motorcraft carb, and the later 86 up style dual exhaust with an off road h pipe and a flowmaster cat back. Then once I get a 94-95 brake booster to complete my rear disc conversion I should be pretty much set.